What are JWT(Json Web Tokens)?

• Pronounced as jot(JWT)
• It is a means of transferring information between parties using JSON object.

It consist of three parts separated by dot(.)

• Header.payload.signature
• like xxxx.yyyy.zzzz

a typical JWT look like this :

Header contains two parts

• type of token which is JWT.
• hashing algorithm

Payload contain claims which can be reserved,public,private.

Signature for creating signature we take encoded header,encoded payload and sign that.

How JWT works?

An example

• when a user sends a post request to the server (like login), a JWT will be returned.
• the server will check for a valid JWT .
• if there is a valid JWT user will be allowed to access the protected page!

Why use JWT?

-small in size

• more secured due to digital signature
• easier to process. -stateless authentication (user is not saved in server memory)
• reduces need to go back and forth to database for information

Common Use Cases :

• Authentication
• Authorization
• Information exchange